Fluid handling devices are becoming increasingly popular and there is an increased demand for fluid handling devices. One type of fluid handling device is an electrically-actuated valve. Electrically-actuated valves are used in a variety of situations to control various types of fluids. Often, electrically-actuated valves are implemented where relatively fast response times are desired or where a fluid-actuated valve cannot be implemented or is not desired. In order for an electrically-actuated valve to be efficient, it should consume minimal power, operate with low noise, and be cost effective to manufacture. In many applications, it is also important that the electrically-actuated valve provide an accurate and consistent fluid distribution.
One type of an electrically-actuated valve that attempts to meet the above criteria is a solenoid valve. Solenoid valves however, are generally limited in size, and in order to obtain adequate performance, a solenoid valve typically consumes a substantial amount of power. The power consumption of a solenoid valve, in some circumstances, is unacceptable. Furthermore, in some applications, it may be desirable to retain the valve in a specific open or mid-point position. If this position requires continuous actuation of the solenoid, the valve will likely consume a substantial amount of power thereby increasing the cost associated with operating the valve. In addition, solenoid valves are often expensive, large, and sometimes create an audible clicking noise as they are actuated that may be undesirable. Furthermore, the electromagnetic field generated by the solenoid valve can present problems in certain environments.
Another solution has been the use of shape memory alloys that transform shape and/or size when heated. Shape memory alloy actuated valves provide an advantage over the previously mentioned prior art solution as they can typically be manufactured smaller and generally consume less power than solenoid-actuated valves. Although shape memory alloy actuated valves provide an adequate solution for single valve systems, prior art approaches have required an excessive number of parts when incorporated into a valve assembly including two or more valves. This is because in the past, each individual valve of a valve assembly required its own shape memory alloy element to actuate the valve. This configuration results in an excessive number of parts and a complex assembly process that is difficult to automate.
Therefore, there is a need in the art for a shape memory alloy actuated valve system with a reduced number of parts that can be made cheaper and more efficient. The embodiments described below overcome these and other problems and an advance in the art is achieved.